Ship construction.



A. MCDOUGALL'.

SHIP CONSTRUCTON.

APPLmcATloN msn ocT. 9, 191e.

man@ Feb. 26, 191s.

All

IN VEN TOR.

ALEXANDER, MCDUGALL, 0F DULUTI-l, MNNESOTA.

SHIP CONSTRUCTION.

VSpecification of Letters Patent.

Patented leb. 26, llfld..

Application led October 9, 1916. Serial No. 124,525.

To all whom t may concern.'

Be it known that l, ALEXANDER McDou- GALL, a citizen of the, United States, residing at Duluth, in the county of St. Louis and State of Minnesota, have invented certain new and useful Improvements in Ship Constructions, of which the following is a specification, reference being had therein to the accompanying drawing.

My present invention consists of certain improvements in ship construction and relates particularly to the framing of steel ships and is especially applicable to such in which it is desired to form a double bottom and having a plurality of compartments between the bottoms for use as water ballast tanks, for carrying liquid fuel or the like.

For a ready comprehension of the objects of the invention and a comparison with the ordinary practice in such construction, l will relate that the bottom frames of the ordinary steel ship extend from the center keelson to within a short distance of each side, that is, that portion of the frame composed of a single piece of metal. The in* dividual pieces of side frames terminate a short distance above and beyond the ends Yof the bottom frames and the space thus formed intermediate these adjacent ends is spanned and cooperatively unite: the lower ends of the side frames with the bottom `frames by suitable bracket plates, the outer edges of which are rounded, forming the bilge of the ship. rllhis form of corner or bilgc also provides means for an angle plate running fore and aft and terminating the compartments intermediate the double bottoms and to which the upper bottom or tank top is attached by suitable angles.

rllhese bracket plates are riveted to the side frame and fastened to the tank top by angle irons.

They are also faced with angle irons along their inner edges and to which the inner bilge plates are fastened.

lt is evident that this form of corner or bilge necessitates very expensive fabricated construction and deprives the hold of the vessel of considerable carrying capacity, with the only possible advantage, which to a large `degree is theoreticahof providing a rounded bilge. j

This rounded bilge is found in many cases to have other-,disadvantages in that it permits of abnormal rolling of a shipthus coustructed and to overcome which, bilge-keels are fixed thereupon in an attempt to restore the stability afforded by the corner that would have been formed by the direct 1neeting of the floor frames with the side frames as disclosed in my novel plan of framing.

` The inner bottom or tank frames, as they are called, are made by vertical plates full depth of the tank riveted to upper and lower floor beams and where not acting as division walls for the various compartments into which the tank is divided, are provided with numerous manholes through which workmen may pass in building, repairing or painting, as the case may be.

The tank or double bottom is usually divided into six or more compartments by the center keelson or bulkhead which extends the full length of the ship and two or more thwartship bulkheads the full width of the ship. rl`hese may again be subdivided into smaller compartments by vertical plates and angles, all of which require additional holes and entrance means for workmen and veryV obviously complicate the construction. llt has been proven repeatedly and beyond question that this complicated form of cellular construction of ships bottom is very hard to maintain in proper shape and repair and its inaccessibility causes neglect and unseaworthy conditions, besides the great initial expense.

The object of this invention is to materially lessen the cost of construction and quantity of material necessary in an improved form of hull having Vall the advantages, number of compartments, et cetera, of the ordinary ship and a form of construction much more easy of access for repairs, and the like, with the added advantage of the direct use of a much larger proportion of mill-run material.-

Another object is to provide a form of ship construction and arrangement of framing admirably adapted to the standardization of ships hulls which is a phase of the ship building industry rapidly becoming a necessity. Y

Other objects and advantages of my novel form of framing will appear in the further description of the invention and particularly pointed out in the claims.

ln'the accompanying drawings forming partof this application and in which like reference characters indicate like parts.

shown, may be riveted tothe backs of the Y towardy the center stanchions.

The bottom truss is formed of two separate units of fabricated construction each consisting of a straight horizontal channel licor bar, l and a second similar though preferably heavier bottom bar 2, spaced the requisite distance below the bar 1 Vto form desired depth of tank. This bottom bar inclines slightly upwardly toward the side of the frame just suflicient to form the necessary deadrise and is united to the floor bar l, at the innerend thereof, by means of a short vertical channel 3 with its back tightly riveted to the backs of the channels V1 and 2 and ,half way between the center of the frame and each side is another vertical ychan-nel a fastened in the same manner. Upon each side of the frame and at the extreme outer ends, the two channels are united by the side frame 5 which is also a channel bar and riveted back to back thereto, thusl forming va practically square corner though slightly obtuse due to the upward inclination of the channels 2.V The side channels 5 extend upwardly and similarly unite the two outer ends of channels 6 and 7 which together with their cross braces 8 and central connection constitute the upper deck truss which is similar to the bottom truss except that it is inverted, the beam 7 inclining downward toward the lsides from the center to form the necessary camber. ,This forms the upper corners of the frame practically squarel except for the inclination of the beam 7 which makes the angle of the corners slightly obtuse and veryY similar to those of the lower corners.

- The deck channel 7 may be bent sharply at its center and the inclination toward the sides perfectly straight or it may be arched gradually as preferred.

, I have shown vcenter channel stanehions 9 asoccurring intermediate the hatch openings in the upper deck and the opposite ends of which are securely united to the bottom truss of each respective frame. Y

Between the abutting ends of the two halves 'of' the bottom truss extends longitudinally the hull the central bulkhead plate lOrto which plate the foreandaft angles of the channels 3 are securely riveted, thus formlng a secure and strong bond: in the center of the-truss.

It is evident that Ya bulkhead plate,l not channels 1 and 2 between the center bulki ,head and theV sides wherever desiredf to forma thwartship bulkheadand when it is desired' to subdivide these. cempartments,

athwartships, bulkhead plates 11 may be secured to the vertical channel braces 4 and the space from the center to the sides is divided into two equal parts.

Upon the licor plates which extend to the sides of the hull, longitudinally extending angle bars l2 are used at the junction of the side frames with the floor channels l and behind which against the skin of the ship, between the side frames a suitable waterproof cement filling is used as indicated at 18.

While I have shown stanchions 9 as occurring midway between the hatches and extending to the tank top or floor of the hull, I wish it to be understood that these may be dispensed with, if desired, and the center of the top truss, that is, the two channels 6 and 7 be united by short pieces Aof channel similar to the pieces 8 and two ble in all directions and requiring the least number of manholes or openings for construction or maintenance.

Any desired arrangement of plating forming the skin of the ship or the tank top may be employed.

Having thus described my invention what I claim as new and desire to secure by Letters Patent, is: Y

1. A ships thwartship frame composed wholly of channel bars, the backs of which are riveted to each other, the lower horizontal portion of the frame consisting of two oppositely disposed sections, each section comprising an upper straight horizontal channel bar and a lower inclined straight channel bar spaced apart and united by short vertical channel bars, the upper Ihorizontal portion of the frame consisting of a lower straight channel bar extending from side to side of the frame and two inclined channel bars placed end to end, spaced from and united with the lower straight channel bar and forming the upper member of said portion of the frame, and single vertical side members uniting the ends of said lower and upper portions substantially as described.

2. A thwartship frame for ships hulls comprising a truss forming the bottom of the frame, composed of a plurality of straight horizontal members, two straight opposed members upwardly inclined from and an upper truss cach having Straight horizontal inner chords and straight outer chords converging toward the inner chords from the center 0f the frame, single vertical members uniting the ends of the trusses and forming the sides of the hull, a single member uniting the centers of the trusses and short vertical members uniting the chords of each truss intermediate of the center and the ends thereof, substantially as described.

et. The combination with a ships hull substantially rectangular in cross-section and having a plurality of single thwartship upper deck frames intermediate of the hatches thereof, of one of said frames having a thwartship beam spaced therefrom and below the same, a single member centrally uniting said spaced beamsn and extending to the lower portion of the hull and two short vertical members uniting the spaced beams intermediate of the center and the ends thereof.

5. The combination with a ships hull substantially rectangular in cross-section, the framing of which is composed chiefly of channel bars, and having hatches therein, of a plurality of fore and aft spaced channel bars intermediate ofthe hatches and upon which the upper deck is supported, a channel bar spacedbelow and parallel with one of the first mentioned channel bars and fixed thereto, channel bars spaced apart vertically and attached to each other forming the lower portion of the hull frame, a central single channel bar stanchion intermediate of each pair of hatches and attached at one end with its back against the backs of the two lower vertically spaced channel bars and at its opposite end with its back against the backs of the two upper vertically spaced channel bars and single channel bars at each side of the frame uniting the ends of the upper and lower portions thereof, substantially as described.

In testimony whereof l hereunto affix my signature in the presence of two witnesses.

ALEXANDER MCDOUGALL. Witnesses:

A. C. DUNN, S. Gmo. STEVENS. Y

@epics of this patent may be obtained for ve cents each, by addressing the Gommissioner of Patents,

Washington, D. C. Y 

